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Anonymous users2024-01-24(1) The smell of a substance belongs to the physical properties of a substance;
2) Take a small amount of the liquid on the pH test paper, and measure pH=4, indicating that the white vinegar is acidic;
3) Calcium carbonate, the component of scale, can react with acidic substances to produce carbon dioxide, so the phenomenon seen is the generation of bubbles; The acid that can remove scale is dilute hydrochloric acid or dilute nitric acid, and dilute sulfuric acid is generally not used, because dilute sulfuric acid will produce slightly soluble calcium sulfate with calcium carbonate, which will prevent the reaction
Therefore, the answer is: (1) physics; (2) acidic; (3) There are bubbles to produce dilute hydrochloric acid (or dilute nitric acid).
1 smell can be distinguished 2 freezer frozen ice for vinegar, and vice versa for alcohol. 3 Add water in a ratio of 1:10 and dip it to taste. 4. Take a small amount, add some edible alkaline noodles, bubble into vinegar, and vice versa. The above four can be distinguished without leaving the kitchen.
It is recommended to wipe it clean, and then open the window for ventilation. Don't use anything else, it won't be good to damage the structure of the wooden floor.
You can take a bottle of mineral water, don't have water, open the cap and put it horizontally on the cooking table, wait for a few minutes or hours, and just take the lid and close it. >>>More
Vaseline can be used to lubricate the skin in cold weather and prevent skin dehydration.
Generally, fines will be imposed, food safety is very important, if the seasoning expires, it will cause food safety hazards. Therefore, the industrial and commercial department will impose fines and confiscate expired food.